We seek a NIDA Center for Social Work Research Development to advance multi-sector service delivery for drug, alcohol, and co-morbid mental health and HIV risk problems to underserved populations. The CAP-IT Center (Co-morbidity and Addictions Prevention, Intervention, and Treatment) will position our School of Social Work for national leadership in producing scientific knowledge benefitting the larger addictions field. Our core aim is to increase knowledge related to multi-sector addictions interventions for underserved populations with co-morbid mental health and HIV risk problems. This research core covers three focal areas: 1) the delivery or coordination of multi-sector addiction prevention and treatment programs in underserved populations with co-morbid mental health and HIV risk problems. 3) The cost and burdens of addictions and co-morbidity services from different sectors (alcohol and drug, mental health, primary care, social services, juvenile justice education, and informal) and their relationships to service use and outcomes. Our infrastructure aims are 1) To enhance faculty research capacity. 2) To establish an ongoing support system for research. 3) To develop fundable proposals. We will support the research agenda and build our infrastructure through consultation from nationally recognized interdisciplinary experts; Research Triangle Institute (R.T.I) economists; and faculty from Washington University's (W.U.) Department of Psychiatry, and Division of Health Behavior Research. Our infrastructure will include technical staff support, seminars and workshops, facilities, and funding for pilot studies. Outcomes will include: 1) Submission of NIDA RO1's and K mechanisms, 2) Dissemination of our addictions research policy and practice implications through newsletters, a center web page, listserve mailings, and conference presentations. 4) Publications in key peer reviewed journals focusing on drug and alcohol use, addictions, and co- morbidity.